This invention relates to a device and non-invasive surgical method for treating gastroesophageal reflux disease. More specifically, it relates to an anti-reflux valve prosthesis and associated instrumentation for its peroral placement and in situ fixing at the gastroesophageal junction, to prevent the reflux of gastric contents into the esophagus in the treatment of gastroesophageal reflux disease in a patient.
Gastroesophageal reflux disease (GERD) is the commonest cause of dyspepsia, affecting some 30% of the United States adult population intermittently and some 10% on a continuous and troublesome basis. Gastroesophageal reflux disease produces heartburn, abdominal pain and regurgitation of acid-containing gastric contents into the esophagus and pharynx. It may also lead to alteration of the lining of the esophagus (Barrett""s Esophagus), which may go on to produce esophageal cancer. Current methods of treating GERD include powerful antacid medication therapies and surgical interventions.
Medication therapy with powerful antacids is directed at treating the symptoms of GERD, and is necessarily not curative. Furthermore, medication-based therapies are not always fully effective, as reflux is not prevented and the esophagus may continue to be exposed to gastric content.
Surgical intervention typically involves either open surgery (performed through the abdomen or the chest) or laparoscopic surgery (performed through one or more incision access ports inserted through the abdominal wall), and the re-sectioning of tissue or the implanting of a prosthetic device. Although surgical interventions can be curative, these treatments are seriously invasive and have the attendant risk of such procedures. Despite the risk, the field has been motivated to provide solutions to the GERD problem, which has resulted in the development of a number of surgically implantable anti-reflux valve prosthetic devices. Prior anti-reflux valve prostheses are essentially one-way valves implanted at the gastroesophageal junction using open or laparoscopic surgery. The implanted prosthesis allows normal swallowing to take place in an orthograde manner while preventing the reflux of gastric contents from the stomach into the esophagus.
Examples of surgically implanted esophageal anti-reflux valve prostheses include the devices of: Godin (U.S. Pat. No. 5,314,473) which discloses a one-way, antivalve comprising a flattened tubular part associated with an annular fixing element; and Reich (U.S. Pat. No. 4,846,836) which discloses a bi-directional valve and housing for similar purposes. These devices were developed to be inserted into the gastro-esophageal junction via open or laparoscopic surgery and fixed there. The purpose was to permit the unidirectional passage of ingested materials into the stomach while preventing the reflux of gastric content of the stomach into the esophagus. Typically, these devices require suturing or other means to fix them to the tissue of the esophagus.
Generally, all of these prior devices and methods require surgical invasion of a body cavity and breach of the body membrane in some fashion (e.g., open surgery or laparoscopy) in order to accomplish their utility. However, such invasive surgical interventions are too frequently complicated by problems such as stricture formation, xe2x80x9cgas bloat,xe2x80x9d or recurrent symptoms of reflux disease. Additionally, the results obtained by gross surgical treatment can be technique-dependent and vary significantly from surgeon to surgeon.
In view of the preference for minimally invasive forms of surgery there is a need in the art for GERD treatments which can be fully accomplished without surgically compromising the integrity of a patient""s body membrane. Applicant has invented a peroral procedure for the insertion and implantation of an anti-reflux valve prosthesis that can address this need. It benefits the field to have an alternative prosthetic device and method that can be practiced to position and fix an anti-reflux prosthesis in place in the esophagus without resort to surgical incision or laparoscopy.
The present invention relates to an anti-reflux valve prosthesis system for treating gastroesophageal reflux disease (GERD) in a patient, which does not require open or laparoscopic surgery to implant. The present invention provides for perorally inserting an anti-reflux valve prosthesis down the lumen of the esophagus, to the gastroesophageal junction, where it is fixed in place. The advantage of this system is that peroral insertion of such a valve eliminates the need for either open formal laparotomy, thoracotomy or a laparoscopic approach using multiple access ports. Peroral installation of an anti-reflux prosthesis has the potential benefits of reducing the trauma, morbidity and hospital stay associated with implantation of anti-reflux valve prostheses relative to other surgical techniques. Furthermore, a system permitting the implantation of a standardized anti-reflux valve in an accurate and reproducible manner has the potential for providing more consistent clinical results than can be achieved with other techniquemethods of treatment.
The prosthesis system comprises an anti-reflux valve prosthesis and a peroral implantation tool for positioning and fixing the prosthesis proximate the distal end of the esophagus of a patient being treated for GERD. The present invention provides a prosthesis that is self-anchoring, having a mounting ring preferably constructed of a memory material supporting an anti-reflux valve. The memory material allows the mounting ring to be acted upon and deformed, but to return to its original shape when the deformation force is removed. The mounting ring is deformed during installation, but automatically returns to its original ring shape upon release. Also, the mounting ring incorporates tissue anchors which fixably engage the adjacent lumenal tissue of the esophagus to hold the prosthesis in place after installation. An anti-reflux valve is supported by the mounting ring. The anti-reflux valve is a normally closed, compliant one-way valve integral with the mounting ring. A variety of one-way valve types are practicable in the present invention by one of ordinary skill in the art. These include sleeve valves, monocuspid, bicuspid and tricuspid valves, hinged disk valves, double hinged valves and heart valves. Typically, the compliant part of a valve has structural supports to prevent the valve from inverting.
A feature of one installation tool is a removable compression collar for encircling the mounting ring and holding it in a compressed condition and for releaseably housing the prosthesis during positioning and prior to implantation. The compression collar is integral with one end of an overtube. The overtube is of a smooth and optionally flexible construction. The distal end of the overtube receives and holds the prosthesis in a compressed configuration during positioning of the prosthesis in the lumen of the esophagus. A further feature of the installation tool is a hollow stylet tube indwelling and slidable in the length of the overtube from the prosthesis at the distal end of the overtube to the handle at the proximal end of the overtube. At its distal end, the stylet is fitted with a normally deflated balloon which is inflatable by passing a gas or liquid (under appropriate pressure) through the hollow of the stylet tube and into the balloon. The deflated balloon is positioned and disengaged from the overtube in concert with the prosthesis. After disengagement, the balloon is inflated to exert pressure on the inside surface of the mounting ring of the prosthesis. The recovery of the memory material of the released mounting ring and the force exerted by the inflated balloon cause the tissue anchors of the mounting ring to engage with the lumenal tissue of the esophagus.
Another aspect of the present invention is a method for using the above tool to implant an anti-reflux valve prosthesis in a patient with GERD. In operation, a compressed prosthesis, housed in the compression collar of the implantation tool, is inserted down the esophagus of an anesthetized patient. When the prosthesis is in a proper position for implantation in the esophagus, the stylet and overtube are slidably positioned so as to disengage the overtube and compression collar from the compressed prosthesis while holding it in position. Upon disengagement, the prosthesis is allowed to auto-expand into position. Then the balloon feature of the stylet is inflated to positively engage the tissue anchor features of the prosthesis with the tissue of the esophagus. After the prosthesis is anchored in position, the balloon is deflated and the implantation tool is removed from the patient.
Another aspect of the present invention is an anti-reflux valve prosthesis system having an implantation tool that uses a circular surgical stapler to anchor an anti-reflux valve prosthesis in place in a patient""s esophagus. The prosthesis is fixed in position by stapling a mounting ring integral with a one-way valve to the lumen wall of the esophagus. The stapler is accomplished by adapting any of a number of circular surgical staplers known in the art (such as in U.S. Pat. No. 5,445,644 to Pietrafitta et al., U.S. Pat. No. 5,411,508 to Bessler, and U.S. Pat. No. 5,104,025 to Main etal. which are hereby incorporated herein by reference) to include the vacuum tissue engagement means of the present invention.
In this embodiment, the installation tool has a tubular body having a length and outside diameter appropriate for passage through the mouth and down the esophagus. A substantially typically circular surgical stapler is mounted on the distal end of this tubular device. The stapler is comprised of four major features: (1) a head for dispensing and driving staples, (2) an anvil for receiving and bending staple points, (3) a tissue engager for engaging and holding lumenal tissue in an annular space between the head and anvil, and (4) a prosthesis holder for juxtaposing the mounting ring of a prosthesis with the engaged lumenal tissue. The relationship of these features is designed for the driving of staple points through the lumenal tissue and the mounting ring to fixably engage the two by then bending the staple points closed against the anvil. Typically, the head contains a series of staples which can be driven by activation of a handle operated outside the patient""s mouth to drive the staples through the esophageal tissue to engage the mounting ring of the prosthesis. Force supplied to these staples drives them through the esophageal tissue, the mounting ring and against an anvil which bends the staples into a closed configuration to fix the tissue with the mounting ring.
The tissues to be stapled are drawn between the head and the anvil, by suction applied to a tubular member disposed between the head and anvil. Once the tissue is drawn between the head and anvil, activation of the handle of the tool sets the staples to permanently fix prosthesis in position in the esophagus. Withdrawal of the tool leaves the prosthesis permanently implanted in the esophagus. There the prosthesis will prevent reflux from occurring. The suspension ring is constructed of an appropriate material of sufficient strength and long term durability to enable the device to be permanently fixed in situ.
The present invention also provides a kit for treating gastroesophageal reflux disease comprising an autoclaveable container containing the prosthesis system described, and optional instructions for its use.
The valve prosthesis of the present invention is constructed of known materials, biologically inert and resistant to the media of stomach content. The prosthesis comprises a mounting ring and integral anti-reflux valve. The anti-reflux valve is an easy-opening one-way valve, implanted so that ingested materials may pass through it in an orthograde direction without significant impediment to their passage. The valve is normally closed, and the pressure differential between the stomach and the esophagus and between the abdominal and thoracic cavities act to maintain closure of the valve.
The mounting ring is typically made of a memory material (such as a nickel titanium alloy, spring steel, or suitable plastic). Similar devices, but without the incorporation of an anti-reflux valve, are known in the art and have been used in the treatment of strictures due to esophageal cancer. The memory material of the mounting ring typically is encased or encapsulated in a suitable biologically and chemically compatible or inert material such as silicone or the like.
In one embodiment of the prosthesis, the mounting ring (from which the valve is suspended) has an outwardly disposed, axial array of tissue anchors, typically, barbed spikes. When the mounting ring is properly positioned in the esophagus, the tissue anchors are implanted into the lumen wall of the esophagus, to fix the mounting ring/valve combination in place. The prosthesis (combination mounting ring and valve) is implanted using an implantation tool described above.
In a further aspect of the present invention, a prosthesis comprises an anti-reflux valve housed inside a cylindrical device made of a memory material which can be fixed in the distal esophagus. Such cylindrical devices have been used (without the incorporation of a valve prosthesis) in the treatment of strictures due to esophageal cancer. An example of such a device is the WALLSTENT(copyright) esophageal endoprosthesis (Schneider USA, Inc.). These devices typically comprise a cylinder of memory metal in close contact with a sleeve of suitable material, such as silicone. The prosthesis is inserted perorally and positioned using an adaptation of the usual tool used for installing such devices. The prosthesis is fixed in place by the expansion of the cylindrical device housing the anti-reflux valve.